Install all junction boxes per NEC regulations. All wires to be connected with UL approved wire nuts. This versatile device allows for easy troubleshooting, modification, and expansion of electrical systems. The 4 terminal junction box typically. This article will provide a step-by-step guide to walk you through the process of safely wiring a 4 way junction box for your home project. Wiring a 4 way junction box is an essential part of any electrical project as it serves as a connector between four different circuits. Removing input power resets the relay. If the product is damaged, DO NOT use it, and.